The present invention relates to medical devices and, more particularly, to devices for protecting against the accidental puncturing of one's skin by the tip of a needle, such as used in a hypodermic syringe.
Hypodermic syringes are commonly used in medicine for dispensing medicines or other fluids into patients, either intravenously or intramuscularly. There is one hazard to their use, however. The sharp needle may prick the skin of the physician or nurse. Now that so many dangerous and highly contagious diseases are prevalent, particularly acquired immune deficiency syndrome (AIDS), it has become increasingly worrisome to many practitioners to dispense fluids by use of hypodermic needles. Still, there is no effective substitute.
Thus, there is a need for a device which may render the use of needles, such as those used with hypodermic syringes and the like, less dangerous.
Many devices have been developed to shield the tip of a hypodermic needle after it has been exposed to potentially dangerous contaminants. These devices include many different types of sheaths and covers, and are generally retractable, to permit the use of the syringe. Such devices commonly include some slidable sheath capable of movement between an extended position in which the tip of the needle is covered, to a retracted position in which the tip is exposed, so that the needle may be used.
For example, U.S. Pat. No. 4,874,383 discloses a Syringe Shield. The disclosed shield is movable from a retracted position in which the needle is exposed, to an extended position in which the needle is covered. By movement into the extended position after use, the user is protected from inadvertent puncturing of the skin. Many other devices have similar properties, such as those disclosed in U.S. Pat. Nos. 4,702,738; 4,723,943; 4,737,144; 4,738,663; 4,747,837; 4,850,994; 4,801,295 and 4,908,023. Each of these devices discloses a different type of shield for covering a contaminated hypodermic needle after use.
U.S. Pat. Nos. 4,752,290 and 4,826,491 disclose Needle Bearing Medical Devices with Three-Position Shields. The disclosed devices are designed to move from a first position in which the needle of the syringe is covered, prior to use, to a second position in which the needle is exposed for use, and then to a third position in which the needle is again covered, after usage, so that the possibility of pricking is avoided.
Such devices, however, do not have universal applicability. There are many instances where a needle may be used other than with a hypodermic syringe.
A needle may be used to introduce a fluid into a "Y-site", i.e. a bifurcated tube having two input ports for receiving fluids to be dispensed into a patient, and one exit port connected to the patient. One input port of the Y-site is conventionally connected to a standard drip bottle, while the other is exposed. The exposed entry port has a diaphragm covering its opening. If a secondary fluid is to be dispensed through the Y-site, a second drip bottle having a tube which terminates in a needle is employed. The needle of that second drip bottle is inserted through the diaphragm of the Y-site, so that the secondary fluid may drip from the second drip bottle through the tube, past the diaphragm and into the patient. In these instances, it is sometimes necessary to retain the needle in position for an extended period, since the purpose of using a drip bottle is to provide fluids slowly over time.
Prior art devices, such as referenced above, lack suitable means for securing the syringe to a Y-site while in use, or for engagement of the Y-site to permit use while protecting the user. Furthermore, prior art devices do not permit the covering of the needle while it is inserted into a Y-site. The construction of these prior art protective devices, in fact, would prevent piercing the diaphragm while the protective sleeve is in its extended position.
One recent patent, U.S. Pat. No. 4,834,716, discloses a Protected Cannula (i.e. a needle) for use in dispensing fluids into a Y-site. The needle is carried within a fixed sleeve, which is used as a covering when the needle is inserted into the Y-site. While this serves to protect the fingers of the user from inadvertent puncture, it does not provide means for affirmatively securing the needle in place in the Y-site. Additionally, the sleeve is not movable with respect to the needle, thereby rendering the needle incapable of use in dispensing medicine directly into a patient's body.
Thus, there is a need for a needle protecting apparatus which may be used either with a Y-site or for dispensing fluids directly into a patient, while protecting against accidental puncturing of the user.
There is a further drawback to the prior art devices. When a hypodermic needle is used to dispense fluids intramuscularly, it is necessary to ensure that the needle extends only a given depth into the patient. Many times this is accomplished by limiting the length of the needle used to dispense the desired fluid. However, this requires the selection of differing needles for different applications, which, in turn requires practitioners to maintain supplies of needles of varying lengths. Since it is also often necessary to maintain supplies of needles having differing diameters, the need to maintain needles of different lengths may lead to the need to maintain several different diameters of needles each of differing lengths. This multiplication of needle sizes and diameters leads to increased cost.
Furthermore, if a shortage of one type of needle occurs, for example a short needle, usage of a needle having too great a length may cause the needle to enter the patient to an excessive depth, hitting a bone or otherwise injuring the patient or limiting the efficacy of the medicine dispensed. A shortage of longer needles would also be injurious, as the dispensed medicine may not be dispensed at the required depth. In either event, it would be useful to provide means for utilizing a standardized length of needle, without the risk of using a needle having insufficient or excessive length.
U.S. Pat. No. 4,356,822 shows a Syringe Assembly which permits the covering of only a portion of the exposed tip of the needle. Although the disclosed assembly permits the locking of a protective sleeve to cover an exposed needle tip, the sleeve is capable of movement in either direction along the barrel of the syringe, so that it is possible that, once covered, the tip may be exposed by movement of the sleeve out of its fully extended position.
Thus, there is still a need for a device for protecting the user from inadvertent exposure of a contaminated needle, by undesired movement of the protective sheath from its extended position into its retracted position after exposure to contaminants.